Download Module 12 Electromagnetic force

Module 12
Electromagnetic force
Physical Science
Lesson 8
Assignment
• Page 311-312
– # 1, 2, 3, 7, 8, 9, 11, 14, 16
Homework
• Test Thursday
• For track team- test Wednesday in PE
1. Photon: a small ________ of ________ that acts
like a _________.
2. Charging by conduction: Charging an _____ by
allowing it to come into ____ with an object that
already has an __________ _____.
3. Charging by induction: Charging an ____
without _______ _______ between the
_______ and a ________.
4. Electrical current: The ___ of ___ that travels
past a _________ ______ in an electric circuit
each ________.
5. Conventional current: _______ that flows
form the _______ side of the ________ to
the ________ side. This is the way ________
is drawn in _________ ________, even
though it is _________.
6. Resistance: the ________ of a ________ to
_______ the flow of _________
7. Open circuit: a _________ that does not
have a __________ connection between the
_____ sides of the __________ source. As a
result, ______ does not ______.
2. For the following situations, use a
solid arrow to draw the force exerted
by the circle with the solid line. Use a
dashed arrow to draw the force
exerted by the circle with a dashed
line.
-
+
-
-
3. The force between the south pole of a
magnet and the north pole of a magnet is
measured. If the distance between the
poles is increased by a factor of 3, how
does the new force compare to the old
one? Is the force attractive or repulsive?
1
1
𝐹= 2= 2
𝑑
3
Distance increase, force decrease by 9
North pole and south pole--- attractive
7. If you were to use a positively
charged rod to charge an object by
induction, what charge will the object
have?
• induction: opposite charge
• So the object will be negative
8. If you were to use a positively
charged rod to charge an object by
conduction, what charge will the
object have?
• conduction: same charge
• So the object will be positive
9. An electrical circuit uses a large voltage
but a small current. Is the energy of each
electron high or low? Are there many
electrons flowing through the circuit or are
there few? Is the circuit dangerous?
• Voltage is energy of electrons so
– Energy is high
• Current is the # of electrons so
– There are few
• Energy is high so the circuit could be dangerous and
should be treated as dangerous
• If you have a low voltage circuit that you need to get
more energy from, you need to increase the current
11. Draw the conventional current
flow in the following circuit.
Be sure you can also draw the correct direction of
the current
14. You have two wires. One is thin
and the other is very thick. When the
same current is run through each wire,
which will get hotter?
• The thin wire
• Wider or thicker wire will have less resistance and
produce less heat.
• If I say your friend is holding two extension cords
that are the same length but the one in their left
hand is warmer than the one in the right hand,
which one is thicker?
• The thicker one will be the cooler one
16. Three lights are in a circuit. When
one burns out, they all go out. When
the burnt-out one is replaced with a
good light, the other two lights work
again. Are the lights wired in a parallel
circuit or a series circuit?
• Series circuit
Also know…
• for an object to be magnetized, the atoms
must be aligned.
• When you cut a magnet in half, you now have
4 poles: 2 north and 2 south